A Trio of Super-Earths (artist’s impression)

Artist’s impression of the trio of super-Earths discovered by an European team using the HARPS spectrograph on ESO’s 3.6-m telescope at La Silla, Chile, after 5 years of monitoring. The three planets, having 4.2, 6.7, and 9.4 times the mass of the Earth, orbit the star HD 40307 with periods of 4.3, 9.6, and 20.4 days, respectively.